Advanced oxidation processes, including photocatalysis, have been proven effective at organic dye degradation. Tailored porous materials with regulated pore size, shape, and morphology offer a ...sustainable solution to the water pollution problem by acting as support materials to grafted photocatalytic nanoparticles (NPs). This research investigated the influence of pore and particle sizes of photocatalytic MICROSCAFS® on the degradation of methyl orange (MO) in aqueous solution (10 mg/L). Photocatalytic MICROSCAFS® are made of binder-less supported P25 TiO2 NPs within MICROSCAFS®, which are silica–titania microspheres with a controlled size and interconnected macroporosity, synthesized by an adapted sol–gel method that involves a polymerization-induced phase separation process. Photocatalytic experiments were performed both in batch and flow reactors, with this latter one targeting a proof of concept for continuous transformation processes and real-life conditions. Photocatalytic degradation of 87% in 2 h (batch) was achieved, using a calibrated solar light simulator (1 sun) and a photocatalyst/pollutant mass ratio of 23. This study introduces a novel flow kinetic model which provides the modeling and simulation of the photocatalytic MICROSCAFS® performance. A scavenger study was performed, enabling an in-depth mechanistic understanding. Finally, the transformation products resulting from the MO photocatalytic degradation were elucidated by high-resolution mass spectrometry experiments and subjected to an in silico toxicity assessment.
This work provides new knowledge on natural yellows used in Iran. Seven biological sources were selected based on interviews with dye masters in Isfahan workshops (Iran).
,
,
,
,
,
, and
are ...currently used in these workshops. Aiming to study the dye composition of wool samples dyed with the extracts of the selected biological sources and the changes induced by the dyeing procedures in the original chemical composition of the plant extract, raw materials and dyed wool (by us and in the workshops) were analyzed by HPLC-DAD and UHPLC-HRMS/MS. The main yellows for
are luteolin-
-glycosides. In the other plant sources, the main chromophores are based on 3-
-glycosides of kaempferol, quercetin, and isorhamnetin. In pistachio hulls, myricitin derivatives were detected and we propose their use as markers. Generally, the solutions extracted from the wool displayed a higher amount of more polar compounds, but also a higher amount of aglycones. Importantly, the chromatographic profiles of the samples we prepared compared well with 17th c. yellows in Persian carpets, and therefore can be considered highly characterized references for the study of Persian yellows.
Microbial life present in the marine environment has to be able to adapt to rapidly changing and often extreme conditions. This makes these organisms a putative source of commercially interesting ...compounds since adaptation provides different biochemical routes from those found in their terrestrial counterparts. In this work, the goal was the identification of a marine bacterium isolated from a sample taken at a shallow water hydrothermal vent and of its red product. Genomic, lipidomic, and biochemical approaches were used simultaneously, and the bacterium was identified as
. A high-throughput screening strategy was used to assess the best physico-chemical conditions permitting both cell growth and production of the red product. The fatty acid composition of the microbial cells was studied to assess adaptation at the lipid level under stressful conditions, whilst several state-of-the-art techniques, such as DSC, FTIR, NMR, and Ultra-High Resolution Qq-Time-of-Flight mass spectrometry, were used to characterize the structure of the pigment. We hypothesize that the pigment, which could be produced by the cells up to 62 °C, is prodigiosin linked to an aliphatic compound that acts as an anchor to keep it close to the cells in the marine environment.
Aiming to improve their photocatalytic performance, titanate nanowires (TNW) were modified by Fe and Co (co)-doping, FeTNW, CoTNW and CoFeTNW samples, using a hydrothermal methodology. XRD ...characterization agrees with the existence of Fe and Co in the lattice structure.and the existence of Co
together with the presence of Fe
and Fe
in the structure was confirmed by XPS. The optical characterization of the modified powders shows the impact of the
-
transitions of both metals in the absorption properties of TNW, mainly in the creation of additional 3
energetic levels within the prohibited zone. The effect of the doping metal(s) in the recombination rate of photo-generated charge carriers suggests a higher impact of Fe presence when compared to Co. The photocatalytic characterization of the prepared samples was evaluated via the removal of acetaminophen. Furthermore, a mixture containing both acetaminophen and caffeine, a well-known commercial combination, was also tested. CoFeTNW sample was the best photocatalyst for the degradation of acetaminophen in both situations. A mechanism for the photo-activation of the modified semiconductor is discussed and a model proposed. It was concluded that both Co and Fe are essential, within the TNW structure, for the successful removal of acetaminophen and caffeine.
The development of sustainable biomaterials and surfaces to prevent the accumulation and proliferation of viruses and bacteria is highly demanded in healthcare areas. This study describes the ...assembly and full characterization of two new bioactive silver(I) coordination polymers (CPs) formulated as Ag(aca)(μ-PTA) n ·5nH2O (1) and Ag2(μ-ada)(μ3-PTA)2 n ·4nH2O (2). These products were generated by exploiting a heteroleptic approach based on the use of two different adamantoid building blocks, namely 1,3,5-triaza-7-phosphaadamantane (PTA) and 1-adamantanecarboxylic (Haca) or 1,3-adamantanedicarboxylic (H2ada) acids, resulting in the assembly of 1D (1) and 3D (2). Antiviral, antibacterial, and antifungal properties of the obtained compounds were investigated in detail, followed by their incorporation as bioactive dopants (1 wt %) into hybrid biopolymers based on acid-hydrolyzed starch polymer (AHSP). The resulting materials, formulated as 1@AHSP and 2@AHSP, also featured (i) an exceptional antiviral activity against herpes simplex virus type 1 and human adenovirus (HAd-5) and (ii) a remarkable antibacterial activity against Gram-negative bacteria. Docking experiments, interaction with human serum albumin, mass spectrometry, and antioxidation studies provided insights into the mechanism of antimicrobial action. By reporting these new silver CPs driven by adamantoid building blocks and the derived starch-based materials, this study endows a facile approach to access biopolymers and interfaces capable of preventing and reducing the proliferation of a broad spectrum of different microorganisms, including bacteria, fungi, and viruses.
The escalating antimicrobial resistance crisis urges the development of new antibacterial treatments with innovative mechanisms of action, particularly against the critical priority ...carbapenem-resistant Acinetobacter baumannii (CRAB), Pseudomonas aeruginosa (CRPA) and Enterobacteriaceae (CRE). Membrane-disrupting dodecyl deoxyglycosides have been reported for their interesting phosphatidylethanolamine-associated bactericidal activity against Gram-positive strains; however, their inability to penetrate the Gram-negative outer membrane (OM) renders them useless against the most challenging pathogens. Aiming to repurpose alkyl deoxyglycosides against Gram-negative bacteria, this study investigates the antimicrobial effects of five reference compounds with different deoxygenation patterns or anomeric configurations in combination with polymyxins as adjuvants for enhanced OM permeability. The generation of the lead 4,6-dideoxy scaffold was optimized through a simultaneous dideoxygenation step and applied to the synthesis of a novel alkyl 4,6-dideoxy C-glycoside 5, herein reported for the first time. When combined with subtherapeutic colistin concentrations, most glycosides demonstrated potent antimicrobial activity against several multidrug-resistant clinical isolates of CRAB, CRE and CRPA exhibiting distinct carbapenem resistance mechanisms, together with acceptable cytotoxicity against human HEK-293T and Caco-2 cells. The novel 4,6-dideoxy C-glycoside 5 emerged as the most promising prototype structure for further development (MIC 3.1 μg/mL when combined with colistin 0.5 μg/mL against CRPA or 0.25 μg/mL against several CRE and CRAB strains), highlighting the potential of C-glycosylation for an improved bioactive profile. This study is the first to show the potential of IM-targeting carbohydrate-based compounds for the treatment of infections caused by MDR Gram-negative pathogens of clinical importance.
Three novel bioactive silver–organic networks, namely, the 2D polymer Ag(μ3-PTA)(chc) n ·n(Hchc)·2nH2O (1), the 3D bioMOF Ag2(μ3-PTA)2(μ2-chdc) n ·5nH2O (2), and the 2D polymer ...Ag2(μ2-PTA)2(μ4-H2chtc) n ·6nH2O (3), were constructed from 1,3,5-triaza-7-phosphaadamantane (PTA) and various flexible cyclohexanecarboxylic acids as building blocks {cyclohexanecarboxylic (Hchc), 1,4-cyclohexanedicarboxylic (H2chdc), and 1,2,4,5-cyclohexanetetracarboxylic (H4chtc) acid, respectively}. The obtained products 1–3 were fully characterized by IR and NMR spectroscopy, ESI-MS(±) spectrometry, elemental and thermogravimetric (TGA) analyses, and single-crystal and powder X-ray diffraction. Their structural diversity originates from distinct coordination modes of cyclohexanecarboxylate moieties as well as from the presence of unconventional N,N,P-tridentate or N,P-bidentate PTA spacers. Topological classification of underlying metal–organic networks was performed, disclosing the hcb, 4,4L28, and a rare fsc-3,4-Pbcn-3 topology in 1, 2, and 3, respectively. Moreover, combination of aqueous solubility (S 25°C ≈ 4–6 mg mL–1), air stability, and appropriate coordination environments around silver centers favors a release of bioactive Ag+ ions by 1–3, which thus act as potent antibacterial and antifungal agents against Gram-positive (S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria as well as a yeast (C. albicans). The best normalized minimum inhibitory concentrations (normalized MIC) of 10–18 (for bacterial strains) or 57 nmol mL–1 (for a yeast strain) were achieved. Detailed ESI-MS studies were performed, confirming the relative stability of 1–3 in solution and giving additional insight on the self-assembly formation of polycarboxylate Ag–PTA derivatives and their crystal growth process.
The synthesis and antiproliferative evaluation of novel d‐glucopyranuronamide‐containing nucleosides is described. Based on our previously reported anticancer d‐glucuronamide‐based nucleosides, new ...analogues comprising N/O‐dodecyl or N‐propargyl substituents at the glucuronamide unit and anomerically‐N‐linked 2‐acetamido‐6‐chloropurine, 6‐chloropurine or 4‐(6‐chloropurinyl)methyl triazole motifs were synthesized in 4–6 steps starting from acetonide‐protected glucofuranurono‐6,3‐lactone. The methodologies were based on the access to N‐substituted glycopyranuronamide precursors, namely 1,2‐O‐acetyl derivatives or glucuronoamidyl azides for further nucleobase N‐glycosylation or 1,3‐dipolar cycloaddition with N9‐ and N7‐propargyl‐6‐chloropurines, respectively. N‐Propargyl glucuronamide‐based N9‐purine nucleosides were converted into (triazolyl)methyl amide‐6,6‐linked pseudodisaccharide nucleosides via cycloaddition with methyl 6‐azido‐glucopyranoside. A CuI/Amberlyst A‐21 catalytic system employed in the cycloaddition reactions also effected conversion into 6‐dimethylaminopurine nucleosides. Antiproliferative evaluation in chronic myeloid leukemia (K562) and breast cancer (MCF‐7) cells revealed significant effects exhibited by the synthesized monododecylated purine‐containing nucleosides. A N‐propargyl 3‐O‐dodecyl glucuronamide derivative comprising a N9‐β‐linked 6‐chloropurine moiety was the most active compound against MCF‐7 cells (GI50=11.9 μM) while a related α‐(purinyl)methyltriazole nucleoside comprising a N7‐linked 6‐chloropurine moiety exhibited the highest activity against K562 cells (GI50=8.0 μM). Flow cytometry and immunoblotting analysis of apoptosis‐related proteins in K562 cells treated with the N‐propargyl 3‐O‐dodecyl glucuronamide‐based N9‐linked 6‐chloropurine nucleoside indicated that it acts via apoptosis induction.
The synthesis and antiproliferative evaluation of novel d‐glucuronamide‐containing nucleosides, including molecules comprising N/O‐dodecyl or N‐propargyl substituents at the glucuronamide unit and anomerically N‐linked 2‐acetamido‐6‐chloropurine, 6‐chloropurine or 4‐(6‐chloropurinyl)methyl triazole motifs, and (triazolyl)methyl amide‐6,6‐linked pseudodisaccharide nucleosides, is described. N‐propargyl 3‐O‐dodecyl glucuronamide‐based nucleosides containing 6‐cloropurine motifs revealed significant effects in K562 and MCF‐7 cells and the most active compound showed ability to induce apoptosis.
The increased use of pharmaceutical and personal care products (PPCPs) has contributed to the contamination of water systems and put pressure on the development of new techniques to deal with this ...problem. Acetaminophen (paracetamol), a common analgesic and antipyretic drug, and caffeine, a known central nervous system stimulant, are being used frequently by many people and found in large amounts in wastewater systems. In this work, their removal, by photocatalytic degradation, was promoted using magnetic nanoparticles (NPs) based on iron oxides. Besides being obtained from cheap and plentiful source, the magnetic properties of these NPs provide an easy way to separate them from the solution when the reaction is complete. Three types of hematite-based NPs, one pure (
1
) and two of them composed by a magnetite core partially (
2
) or completely (
3
) covered by a hematite shell, were synthesized and characterized. Sample
2
was the best photocatalyst for both pollutants’ photo-assisted degradation. Under UV-vis irradiation and using a 0.13 g catalyst/L solution, the total acetaminophen and caffeine degradation (20 ppm/150 mL) was achieved in 45 min and 60 min, respectively. The identification of some of the intermediate products was carried out by liquid chromatography in combination with electrospray ionization mass spectrometry. A complementary Density Functional Theory (DFT) study revealed the relative stability of several species formed during the acetaminophen and caffeine degradation processes and gave some insight about the most favorable degradation pathways.
The objective of this study was to identify transformation products (TPs) of citalopram (CIT), an antidepressant drug, in laboratory experiments. Moreover, toxicity predictions and analyzes in ...wastewater samples were performed. For the formation of TPs, raw water was used for the processes of hydrolysis; photodegradation under ultraviolet (UV) irradiation and chlorination. The toxicities were predicted by computational toxicity assessment. The TPs were identified by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF/MS) in broadband collision induced dissociation (bbCID) acquisition mode and product ion scan mode (MS/MS). The probable structures of the TPs under study were established based on accurate mass, fragmentations observed in the MS spectra and prediction tools software. The experiments resulted in seventeen possible identified TPs and their stability and formation was monitored over time in the experiments. Two of these TPs were identified in wastewater samples It was also observed that most of TPs formed were either less toxic then CIT or had a similar toxicity.
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•Elucidated seventeen transformation products of citalopram by UHPLC-QTOF.•Hydrolysis, photodegradation and chlorination experiments under laboratory conditions.•Time profile of TPs formation were monitored.•In silico toxicity assessment resulted in TPs with mutagenic potentials.•Citalopram and two TPs were detected in wastewater samples.
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